Our invention relates to the general type of wheel alignment apparatus disclosed in U.S. Pat. No. 3,804,526, issued Apr. 16, 1974 and assigned to Royal Industries, Inc., the assignee of this application.
In the prior art with which our invention is concerned, it has been determined that the use of an adjustable reflective reference surface and a source and detector for transmitting radiant energy to the reflective reference and detecting energy received back from the reference can be a versatile and useful tool in adjusting the attitude of the axes of revolution of wheels on a vehicle with respect to one or more reference axes of the vehicle. This may also be seen in a copending application, Ser. No. 409,134, filed Oct. 24, 1973, now U.S. Pat. No. 3,963,352 for WHEEL ALIGNMENT APPARATUS, also assigned to the assignee of our invention, together with the patent referred to above, illustrate a progression of improvements that have been necessitated to overcome inefficiencies, high cost or the like, of prior art apparatus and systems.